Subcutaneous wound debridement

ABSTRACT

Disclosed herein are devices and methods of percutaneously treating an ulcerated wound using ultrasonic energy. Some methods include delivering ultrasonic energy to a target tissue located at a position subcutaneous to the ulcerated wound. In some methods, the ultrasonic energy is delivered using an ultrasonic energy delivery device.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/973,344, filed May 7, 2018, which is a continuation of U.S.application Ser. No. 14/475,129, filed Sep. 2, 2014, the entire contentsof which are incorporated herein by reference.

BACKGROUND

There is currently a large and growing population of patients (mostlydiabetic patients) that are likely to suffer a foot and/or ankle ulcerat some point. It is estimated that there are about 26 million diabeticsin the United States alone and that about 4 to about 5.2 million sufferfrom foot ulcers. It is estimated that about 15% to 20% of diabeticpatients fall into this group. The costs of diabetic treatments arecurrently estimated at about $132,000,000 of which about ⅓ is related totreating foot ulcers.

Chronic ulceration of the foot is one of the most common and difficultto treat consequences of diabetes and other neuropathogenic conditions.Diabetic foot ulcerations are noted to occur in 15-25% of diabeticpatients in the course of their lifetime. Diabetic foot ulcerations aresubject to unopposed repetitive microtrauma, compounded by diabeticsystemic comorbidities such as peripheral neuropathy, structuralchanges, and ischemia. Neuropathic feet are also at risk for a Charcotdeformity, which can completely change normal pedal osseousarchitecture, creating increased foci of plantar pressures at risk forulceration.

Neuropathic pedal ulcerations from diabetes and other etiologies arecommon and costly. The statistical morbidity of diabetic foot ulcers issobering and often overlooked. The diabetic population now numbers over26 million people in the United States. The global “diabetic footdisease” is “a potentially devastating complication of a disease that isreaching epidemic proportions . . . someone, somewhere, looses a legbecause of diabetes every 30 seconds of every day.” Andrew Boulton, etal., The global burden of diabetic foot disease, 366. 9498 LANCET 1719(2005). Diabetics, compared to non-diabetics, are 30 times more likelyto suffer a lower extremity amputation over the course of their livesand have a 10 fold greater risk of being hospitalized for bone and softtissue infections. LA Lavery, et al., Risk factors for foot infectionsin individuals with diabetes, 29(6) Diabetes Care 1288 (2006). Diabeticfoot ulcerations precede 85% of all non-traumatic lower extremityamputations. DG Armstrong et al., Guest editorial: are diabetes-relatedwounds and amputations worse than cancer?, 4(4) INT′L WOUND J. 286(December 2007). The five-year mortality after a lower extremityamputation has been shown to be 45%, greater than or equal to that ofother deadly cancers (e.g., colon, lung, and pancreatic). Id.

Foot ulcers may result from a number of factors. Contributing factorsmay include sepsis, arteriopathy, and neuropathy. In some cases, thediabetic condition leads to the generation of avascular tissue atsubcutaneous levels or in deep tissue. An avascular condition andpatient immobility generally lead to pressure and break-down of theaffected tissues. This chronic condition produces break-down of theoverlying skin, which may in turn lead to secondary infection.

Recurrent ulcerations become common in neuropathic patients and increaserisk of local and systemic infection, repetitive hospitalization, andpotential amputation. These wounds can be challenging and have a highrate of recurrence despite successful episodes of wound care.

Current treatments are underwhelming and focus on treating broken skinand address superficial aspects of ulcers. The goal of ulcer treatmentis generally to resolve the ulcer and reduce recurrence. To date, thefocus of treatment has been on promoting the healing of the superficialaspects of the ulcer at the epidermal level and reducing the bacterialburden. The end result of conventional treatments may be reduction inulcer size, complete resolution of the ulcer size, or a recurrence ofthe ulcer.

Moreover, current therapies designed to heal the ulceration areunpredictable, costly and time consuming, and even when successful maynot address underlying etiologies of osseous, scar, or bursa origin andthereby often lead to recurrence in the same location. A recurrence rateof 40% over the four months following healing has been cited byconcensus panels. The International Diabetes Foundation reportsrecurrence rates of over 50% after three years, and notes that “costs ofdiabetic foot disease therefore include not only the immediate episode,but social services, home care, and subsequent ulcers.”

Current treatments may be separated into two types: indirect and direct.Indirect treatments include off-loading of weight and/or pressure fromthe affected area through customized footwear or by using assistivedevices, such as crutches, scooters, etc. Direct treatments includedebridement of the ulcer surface, topical wound dressing to control thewound bed moisture, and adjunctive methods. Adjunctive methods includegrafts/skin substitutes, negative pressure, hyperbaric oxygen, andphototherapy.

Conventional treatments share a number of features. The best outcomesinclude ulcer healing in 50-70% of cases but with a recurrence rateapproaching 100% about three months after the treatment. Most methodsare provider intensive in that repeat procedures are required. Patientcompliance is also an issue the limits the success of any of theseprocedures. Ultimately, current procedures are costly.

In addition to the grave considerations of morbidity, neuropathiculcerations pose a high financial burden. Up to ⅓ of the $116 billion indirect costs generated by the treatment of diabetes and itscomplications has been attributed to treatment of diabetic foot ulcers(Vickie Driver, et al., The costs of diabetic foot: the economic casefor the limb salvage team, 52(3) J. VASCULAR SURGERY 17S (2010)) andannual direct costs of diabetic limb complications are more expensivethan five of the most expensive cancers: breast, colorectal, lung,prostate, and leukemia (Neal R. Barshes, et al., The system of care forthe diabetic foot: objectives, outcomes, and opportunities, 4 DIABETICFOOT & ANKLE 21847 (2013)).

A retrospective nested case-control study found that relative cost ofcare for diabetics with ulcers was 2.4 times higher than diabeticswithout ulcers prior to ulceration, jumping to 5.4 times higher in theyear after the ulcer, and returning to 2.8 times higher two years afterthe ulcer. Furthermore, the 1999 study showed the excess cost of adiabetic foot ulcer was $26,490 in ulcer patients during the year of theulcer episode, persisting at $17,245 in the following year, compared todiabetics without ulceration with excess costs of $4927 and $5110 duringthe same respective time periods measured. SD Ramsey, et al., Incidence,outcomes, and cost of foot ulcers in patients with diabetes, 22(3)DIABETES CARE 382 (1999).

When wound healing is unsuccessful, the costs of amputation and dealingwith post amputation care are considerable as well. A 2011 report showedapproximately $52,000 is reimbursed annually for a Medicare beneficiarywith diabetes and a lower extremity amputation. D. MARGOLIS, ET AL.ECONOMIC BURDEN OF DIABETIC FOOT ULCERS AND AMPUTATION: DIABETIC FOOTULCERS, DATA POINTS #3 AGENCY FOR HEALTHCARE RESEARCH AND QUALITY, U.S.DEPT. OF HEALTH AND HUMAN SERVICES (January 2011). In an analysis of adecade of inpatient admissions (2001-2010), Skrepnek found that of the388.4 million inpatient admissions in the US, 66.1 million involved adiagnosis of diabetes (17%), 2.5 million involved diabetic foot ulcers(4%), and the 10-year total costs of the inpatient national bill was$2.4 trillion for diabetes and $113 billion for diabetic foot ulcers. G.Skrepnek, Foot-in-wallet disease: Tripped up by “cost-saving”reductions, Paper presented at DF Con 2014 (Mar. 20-22, 2014).

Accordingly, a need exists for the further development of systems andmethods for effectively treatment wounds, not just foot/ankle ulcers.

SUMMARY

Disclosed herein are devices and methods of percutaneously treating anulcerated wound using ultrasonic energy. Some methods include deliveringultrasonic energy to a target tissue located at a position subcutaneousto the ulcerated wound. In some methods, the ultrasonic energy isdelivered using an ultrasonic energy delivery device. In someembodiments, the device includes a transducer, a horn, and a needlesecured to the horn. In some embodiments, the device further includes anaspiration conduit and an irrigation conduit. In some methods, a distalportion of the needle of the ultrasonic energy delivery device is or hasbeen positioned at or around the target tissue using a percutaneousapproach.

Some methods further include debriding the target tissue with theultrasonic energy. Some methods further include removing from thesubcutaneous position at least some detritus that may have been producedby the debriding. In some methods, the target tissue comprises at leastone of the following: soft tissue and hard tissue. Some methods furtherinclude delivering fluid to the subcutaneous position. In some methods,the ultrasonic energy is delivered through the needle. In some methods,the ulcerated wound comprises a foot ulcer.

According to some methods, delivering ultrasonic energy to a targettissue includes inserting the distal portion of the needle through afirst access portal via a percutaneous approach, generating ultrasonicenergy at the subcutaneous position, and removing the proximal portionfrom the first access portion; and inserting the distal portion of theneedle through a second access portal via a percutaneous approach,generating ultrasonic energy at the subcutaneous position, and removingthe proximal portion from the first access portion. In some methods,positioning the distal portion of the needle involves the use of anultrasound guidance system.

In some methods, the target tissue located at the subcutaneous positioncomprises ulcerated wound tissue. In some methods, the ulcerated woundtissue comprises bone tissue. In some methods, the ulcerated woundtissue comprises abnormal growth. In some methods, the abnormal growthcomprises at least one of a bony prominence, calcific tissue, andnecrotic tissue.

According to some embodiments, the needle comprises a stainless steelmaterial, and wherein the needle is brazed to the horn. In someembodiments, the needle is a fully hardened hypodermic needle. In someembodiments, the needle includes an exposed portion having a length ofabout 0.75 inches to about 1.5 inches. In some embodiments, the needlehas a gauge of about 12 to about 25.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary embodiment of the deliverydevice disclosed herein, illustrating an example extension and anexample tab.

FIG. 2 is a perspective view of an exemplary embodiment of the stackassembly, illustrating the horn assembly, the crystal stack assembly andthe compressor.

FIG. 3 is an enlarged perspective view of an exemplary horn,illustrating the horn having a groove portion and a slanted tip portion.

FIG. 4 is a longitudinal section of a portion of the horn assembly,illustrating the slanted tip portion having an angle of about 135°.

FIG. 5 is a perspective view of an exemplary horn assembly, illustratingthe horn having an opening for connecting to the mounting member.

FIG. 6 is a perspective view of an exemplary horn assembly, illustratingthe horn assembly being connected to the mounting member.

FIG. 7 is a perspective view of an exemplary crystal stack assembly,illustrating the crystal stack assembly having piezoelectric crystalsand electrodes.

FIG. 8A is perspective view of an exemplary compressor, illustrating thecompressor defining a lumen and having a barbed fitting.

FIG. 8B is another perspective view of the exemplary compressor shown inFIG. 8A.

FIG. 9 is a cross-sectional view of one example of a delivery device,illustrating the irrigation conduit and the vacuum conduit.

FIGS. 10A-10D comprise intraoperative photos illustrating a technique ofpercutaneous ultrasonic debridement via adjacent percutaneous portalsaccording to the present disclosure.

FIGS. 11A-11B illustrate an interdigital ulcer on the right 2^(nd) digitbefore and after an ultrasonic debridement treatment performed accordingto the present disclosure.

FIGS. 12A-12B illustrate a left plantar 1^(st) metatarsal ulcer beforeand after an ultrasonic debridement treatment performed according to thepresent disclosure.

FIGS. 13A-13B illustrate a right plantar hallux ulceration before andafter an ultrasonic debridement treatment performed according to thepresent disclosure.

FIGS. 14A-14B illustrate a left central forefoot ulcer with significantproblematic bursa before and after an ultrasonic debridement treatmentperformed according to the present disclosure.

FIGS. 15A-15B illustrate a left Charcot midfoot ulcer before and afteran ultrasonic debridement treatment performed according to the presentdisclosure.

FIGS. 16A-16B illustrate the left foot of a patient with a failedCharcot reconstruction before and about four weeks after an ultrasonicdebridement treatment performed according to the present disclosure.

FIGS. 17A-17D illustrate the left foot of patient with midfoot Charcotdeformity with severe C-shaped foot and two ulcerations before and afteran ultrasonic debridement treatment performed according to the presentdisclosure.

DETAILED DESCRIPTION

Various embodiments described herein provide systems and methods foraccessing and treating target body tissue, such as necrotic, diseased,or infected tissue with or without a bony prominence using ultrasonicenergy.

It has been found that different tissues respond to different ultrasonicfrequencies. Without being tied to any particular theory, it is believedthat a frequency range from about 25 kHz to about 29 kHz effectivelyremoves pathologic subcutaneous tissues, such as necrotic tissue,abnormal bone tissue, wound tissues, etc., because these tissues aregenerally more dense than normal, healthy tissues. Again, without beinglimited to any particular theory, it is believed that the density of theunhealthy, abnormal tissues is better able to absorb and be removed bythe ultrasonic energy produced by the devices and systems of the presentdisclosure.

According to some embodiments disclosed herein, an ultrasonic device hasbeen developed that provides a consistent, low-cost, and less invasivetreatment option to patients suffering from chronic neuropathic footulceration. Using this device and the methods disclosed herein,undesired necrotic tissue, cicatrix, bursa, or abnormal bone is cut orotherwise removed with concomitant removal of the treated diseasedtissue.

Ultrasonic energy has the potential to address the three main pathologiccharacteristics of chronic neuropathic foot ulceration: avascularity,sub-ulcer prominence, and secondary polymicrobial infection. Ultrasonicenergy promotes neovascularization in experimental and clinicalsettings. Furthermore, the handpiece design and the predeterminedsettings deliver precise focused energy extending approximately 1-2 mmfrom the tip. This system is bactericidal, and it is hypothesized thatthe procedure produces a congruent zone of sterilization. Concurrentdebridement, irrigation, and aspiration via the same handpiece allow forremoval of necrotic tissue, scar, bursa, or any tissue that may be thesource of the sub-ulcer prominence. This procedure allows the surgeon toaddress the wounds from the inside out or deep below the surface toremove pressure-contributing bony prominences, to fenestrate or removeavascular scar or ulcer tissue, and to possibly release growth factorsinto the area.

Several advantages to the procedure are noteworthy. The probe—which isdescribed in greater detail below—does not enter the wound (therebylessening the possibility of inoculating to a deeper level), and theentry wounds (which may be about 5 mm) are small enough to not require asutured closure. The ability to perform the procedure under localanesthetic in a percutaneous fashion to treat the subcutaneouspathologic tissue allows for a wider patient selection on patients withotherwise prohibitive comorbidities or advanced age.

With percutaneous ultrasonic treatment of subcutaneous diseased tissue,functional ambulation without recurrence is a realistic goal. Thistechnique is effective across a wide range of anatomic locations. Forexample, in the foot, the following anatomical locations may be treated:the heel, the Charcot midfoot, the plantar 1st metatarsalphalangealjoint, the planter central metatarsalphalangeal joint, the hallux, andthe interdigital pedal location. In some cases, use of the devices andmethods disclosed herein result in complete healing without recurrence.

In wounds that occur more proximally or in areas near vitalneurovascular structures, use of visual ultrasound guidance may helpavoid those structures and potential adverse sequelae.

In some embodiments, the system includes a delivery device having astainless steel type needle brazed to a horn using a heating process orbrazing process. The brazing or heating processes described herein mayallow for an increase in the length of the stainless steel type needleswhich may be used by a delivery device for accessing and treating targetbody tissue.

An exemplary system according to the present disclosure may beconfigured to percutaneously access and act upon target tissue whilehelping reduce collateral trauma. In some embodiments, using aminimally-invasive ultrasonic system increases the accuracy of removingdiseased tissue when compared to surgical procedures that includesurgical dissections of healthy tissue. In some embodiments, thepercutaneous, minimally-invasive nature of such systems facilitatestreatment of a patient under local anesthesia. This is advantageous inseveral respects, including patient comfort and convenience and avoidingcosts associated with operating room time and general anesthesia.

According to the present disclosure, ultrasonic systems may include adelivery device and a controller that is operatively connected to thedelivery device. In some embodiments, the delivery device is operativelyconnected to a controller via a power line, a vacuum line, and/or anirrigation line. The power line may be connected to the controller via awired connection. In some embodiments, the controller may be configuredto communicate with the delivery device via a wireless communication ora combination of a wired communication and a wireless communication.

In some embodiments, the delivery device is configured to transmitultrasonic energy to a percutaneous ulcerated wound site at a pre-tunedfrequency selected to debride ulcerated wound tissue. In someembodiments, the target ulcerated wound tissue comprises subcutaneousnecrotic tissue. In some embodiments, the target ulcerated wound tissuecomprises abnormal bone tissue, such as a bony prominence or some othergrowth that may result from excessive pressure. In some embodiments, thetarget tissue comprises a mixture of both bone tissue and softer,diseased tissue.

FIGS. 1 and 2 illustrate a delivery device 102, which according to someembodiments, includes housing 112 and stack assembly 138. In someembodiments, delivery device 102 includes a removable cap over a distalend of delivery device 102.

In some embodiments, housing 112 includes at least two separateportions. For example, as illustrated in FIG. 1, housing 112 includesnose portion 116, body portion 118, and tail portion 120.

In some embodiments, as discussed in more detail below, the housingincludes a portion configured to form part of an irrigation conduit. Forexample, as best illustrated in FIG. 1, nose portion 116 includesportion or sleeve 117. In this example, sleeve 117 defines an innerlumen or channel which forms part of an irrigation conduit.

In some embodiments, sleeve 117 has an insertion portion 121 thatextends to a terminal end and is adapted for percutaneous insertion.Insertion portion 121 of sleeve 117 may be any suitable size. In someexample embodiments, insertion portion 121 has a size of about twelvegauge or less, about twelve gauge to about twenty-five gauge, or aboutfourteen gauge to about twenty-two gauge.

In some embodiments, the size of insertion portion 121 is dictated bythe procedure in question. For example, in some embodiments where woundtissue in the foot or ankle is to be debrided, insertion portion 121 mayexhibit a larger gauge and/or a wider lumen than would be the case or adifferent procedure. In some embodiments involving wound tissue of thefoot, insertion portion 121 may further comprise a stronger materialthan would otherwise be used. In some embodiments, a wider and/orstronger insertion portion may better debride bone tissue than would anarrower, weaker insertion portion.

Insertion portion 121 may have a lateral width of any suitable size. Insome example embodiments, insertion portion 121 has a lateral width ofabout 2.5 mm or less, about 2.2 mm to about 0.4 mm, or about 2.1 mm toabout 0.5 mm. In some embodiments, insertion portion 121 has a lateralwidth of at least about 2.5 mm.

The length of insertion portion 121 may be any suitable size. In someexample embodiments, the length of insertion portion 121 is about threeinches to about 0.25 inches, about 2.7 inches to about 0.5 inches, orabout 2.5 inches to about 1.0 inch.

In some embodiments, the terminal end of insertion portion 121 is formedwith a sharp angle or in some embodiments is squared off.

Insertion portion 121 may leave the exposed portion of needle 136 at anysuitable length. In some embodiments, insertion portion 121 may leavethe exposed portion of needle 136 at a length of about 10 mm or less,for example between from 2 mm to about 10 mm.

In some embodiments, insertion portion 121 may leave the exposed portionof needle 136 at a length of at least about 7 mm. In some embodiments,the length of the exposed portion is between about 7 mm and about 15 mm.In some embodiments, the exposed portion of needle 136 is at least about0.75 inches, at least about 1 inch, or at least about 1.5 inches. Insome embodiments, the exposed portion of needle 136 is between about0.75 inches and about 1.5 inches, between about 0.9 inches and about 1.1inches, or between about 1 inch and about 1.05 inches. In someembodiments, the exposed portion of needle 136 is about 1.032 inches.

In some embodiments, as best illustrated in FIG. 1, sleeve 117 may beintegrally formed as part of nose portion 116. In some embodiments,needle sleeve 117 is separate from and connects to nose portion 116.

Sleeve 117 may be formed of a biocompatible material suitable fordampening products of ultrasonic energy (e.g., heat and vibration). Insome embodiments, sleeve 117 is coated with an echogenic material. Insome embodiments, sleeve 117 is formed of a material exhibiting adifferential echogenicity to that of needle 136. In such embodiments,both needle 136 and sleeve 117 facilitate ultrasonic imaging andseparate identification during percutaneous insertion.

In some embodiments, nose portion 116 is configured to function as aguide for needle 136 during ultrasonic vibration.

In some embodiments, as illustrated in FIG. 9 and discussed in moredetail below, nose cone portion 116 defines channel 119 for enablingand/or directing fluid flow into an incision site. The fluid flow mayact to remove heat buildup caused by friction.

In some embodiments, to prevent or limit air from being delivered to anulcerated wound tissue site from the irrigation conduit, an ultrasonicsystem is configured to evacuate air from the irrigation conduit. Noseportion 116 may be formed from substantially clear material which allowsa user to determine whether any air bubbles exist in the irrigationconduit.

In some embodiments, housing 112 may define a portion to facilitate aconnection to irrigation line 110. For example, as best illustrated inFIG. 1, body portion 118 defines extension 130 which enables deliverydevice 102 to connect to irrigation line 110. In some embodiments, asbest illustrated in FIG. 1, extension 130 defines a hollow lumen havingan inlet.

Extension 130 may be configured such that irrigation line 110 slidesover the outer surface of extension 130. The outside surface ofextension 130 may have a luer type taper on the outside surface ofextension 130 which is configured to connect to irrigation line 110.

Extension 130 may have any suitable shaped cross section, such as, forexample, a cylindrical cross section or a substantially square-shapedcross section. In this example, extension 130 forms part of theirrigation conduit. In another example, extension 130 may have a barbfitting to connect to irrigation line 110. In some embodiments,extension 130 may be referred to as a tube fitting.

As illustrated in FIG. 1 and discussed in more detail below, in someembodiments, tail portion 120 defines opening 128 which allows vacuumline 108 and power line 106 to connect to delivery device 102.

In some embodiments, housing 112 has a substantially cylindrical-shapedcross section. In some embodiments, housing 112 may a different shapedcross section, such as, for example a substantially square-shaped crosssection.

The above-described separate portions of housing 112 may be configuredto connect to each other using any suitable method. For example, in someembodiments, using glue, nose portion 116 may be configured to mate withand connect to a first end of body portion 118, and tail portion 120 maybe configured to mate with and connect to the opposite end of bodyportion 118.

Housing 112 may be formed of any suitable material including moldedplastic and/or acrylonitrile butadiene styrene.

In an embodiment where housing 112 is designed to include separateportions such as the portions described above, this design may provide acost effective method for producing a low cost ultrasonic hand piece.

A cap may be configured to be removably connected to housing 112. Forexample, a cap may be connected to nose portion 116 and removed prior toperforming a debridement procedure. In some embodiments, the cap isconfigured to removably connect to nose portion 116 by employing a luertaper interface.

In some embodiments, the cap is configured to seal the fluid system ofan ultrasonic system. Such a configuration enables the ultrasonic systemto be primed and prepared for surgery.

In some embodiments, as best illustrated in FIG. 2, stack assembly 138includes horn assembly 140, crystal stack assembly 142, and compressor168.

In some embodiments, delivery device 102 includes a mounting member. Forexample, as illustrated in FIG. 6, delivery device 102 includes mountingmember 152.

In some embodiments, horn assembly 140 is configured to connect tomounting member 152. For example, as illustrated in FIG. 5, in someembodiments, opening 150 may define a threaded portion which isconfigured to mate with and connect to a threaded portion of mountingmember 152. FIG. 6 illustrates one example of mounting member 152 beingconnected to horn assembly 140. It should be appreciated that hornassembly 140 may connect to mounting member 152 in any suitable manner.

In some embodiments, horn assembly 140 includes mounting member 152.That is, in these embodiments, mounting member 152 is not a separatecomponent of horn assembly 152, but rather is formed as a single,integral component of horn assembly 152. For example, horn 144 andmounting member may be formed as a single component.

In some embodiments, horn assembly 140 includes needle 136 and horn 144.In some embodiments, needle 136 is a generally hollow tubular memberwhich defines a lumen. As illustrated in FIGS. 2, 5, and 6, needle 136may have distal portion 137 and proximal portion 139.

Distal portion 137 is preferably adapted for percutaneous insertion.Distal portion 137 may be formed at a sharp angle or may be squared off.In some embodiments, distal portion 137 may have serrated edges or othersurface features for enhancing ultrasonic debridement.

Distal portion 137 may have any suitable size. In some exampleembodiments, distal portion 137 has a size of about 12 gauge or less,about 12 gauge to about 25 gauge, or about 14 gauge to about 22 gauge.

Distal portion 137 has a lateral width of any suitable size. In someexample embodiments, display portion 137 has a lateral width of about2.5 mm or less, about 2.2 mm to about 0.4 mm, or about 2.1 mm to about0.5 mm.

According to some embodiments, distal portion 137 has an inner and anouter diameter of any suitable size. In some embodiments, the innerdiameter is between about 0.03 inches and about 0.1 inches, betweenabout 0.05 inches and about 0.08 inches, between about 0.06 inches andabout 0.07 inches. In some embodiments, the inner diameter of distalportion 137 is about 0.063 inches. In some embodiments, the outerdiameter is between about 0.04 inches and about 0.15 inches, betweenabout 0.06 inches and about 0.1 inches, between about 0.07 inches andabout 0.08 inches. In some embodiments, the outer diameter of distalportion 137 is about 0.076 inches.

The length of distal portion 137 may be any suitable size. In someexample embodiments, the length of distal portion 137 is about 3 inchesto about 0.25 inches, about 2.7 inches to about 0.5 inches, or about 2.5inches to about one inch.

In some embodiments, needle 136 is formed of an echogenic, biocompatiblematerial suitable for conveying ultrasonic energy. For example, needle136 may be formed of a stainless steel alloy. In some embodiments,needle 136 may include a stainless steel hypodermic needle. In someembodiments, needle 136 may be formed from a 174 precipitant hardenedstainless steal. In some embodiments, needle 136 includes a heathardened stainless steal. In some embodiments, needle 136 includes awork hardened stainless steal, such as 300 stainless steel.

In some embodiments, needle 136 may have a bevel of about forty-fivedegrees to facilitate insertion into the surgical site.

In some embodiments, as best illustrated in FIG. 1, sleeve 117 andneedle 136 are positioned such that needle 136 has a covered portion andan exposed portion.

In some embodiments, sleeve 117 may be configured to reduce unwanted,collateral transmission of heat, ultrasonic energy, or other byproductsof the ultrasonic energy being conveyed along the covered portion ofneedle 136. Sleeve 117 may reduce or eliminates damage to non-targetbody tissues as a result of unwanted transmission of ultrasonic energy.

In operation, needle 136 vibrates at the surgery site and breaks upcertain tissue such as scarred tendon tissue, osteophytes, boneyprominences, and calcifications. Needle 136 may be configured to directthe aspiration flow from the bore of needle 136 back to collector 192.

In some embodiments, horn 144 is configured to compress piezoelectriccrystals and amplify ultrasonic vibration. In some embodiments, hornassembly 140 may have a tip portion configured to enable or allow for amore durable connection between horn assembly 140 and needle 136. Forexample, as illustrated in FIGS. 3 and 4, horn assembly 140 has tipportion 145. In this example, tip portion 145 defines slant portion 147having an angle (“θ”). In one example, θ is about 135°. Slant portion147 enables for a more durable connection between horn assembly 140 andneedle 136. In this example, slant portion 147 slants inwardly. In thisexample, this cupped-shaped portion allows for the brazing material topool into said portion.

In some embodiments, horn 144 defines an opening to connect to othercomponents of delivery device 102. For example, as illustrated in FIG.5, horn assembly 140 defines opening 150 which enables horn assembly 140to receive mounting member 152. In one example, mounting member 152connects to horn 144 via a threaded connection. It should be appreciatedthat mounting member 152 may connect to horn 144 in any manner.

In some embodiments, as described above, horn assembly 140 includes horn144 and needle 136. In some embodiments, horn assembly 140 includes horn144, needle 136 and mounting member 152. In some embodiments, horn 144and mounting member 152 are formed as a single integral component.

Horn 144 may be made of a metal such as stainless steel. In someembodiments, both horn 144 and needle 136 are made of only stainlesssteal.

In some embodiments, mounting member 152 defines a bore or lumen thatforms a portion of the vacuum conduit and directs aspiration flow fromhorn assembly 140 to a lumen defined by compressor 168.

In some embodiments, mounting member 152 is made from titanium, whichmay allow for stack assembly 138 to resonate at a proper frequency(e.g., between about 25 KHz and about 30 KHz). In some embodiments, thedesired frequency is between about 25 kHz and about 29 kHz.

Mounting member 152 may be frictionally fit, adhered, welded, orotherwise secured within housing 112. In some embodiments, crystal stackassembly 142 is disposed around mounting member 152.

In some embodiments, using a material (e.g., a brazing material), needle136 is connected to horn assembly 140 by employing a brazing process ora heating process. During the brazing process, the brazing materialmelts the brazing material to cause needle 136 to join together withhorn 144 to form a single contiguous horn assembly. The meltingtemperature of the brazing material alloy is preferably low enough suchthat needle 136 will not anneal during the brazing process. The meltingtemperature of the brazing material facilitates fixing the needle to thehorn.

During the brazing process, needle 136 may be in a condition that can beaffected by an elevated temperature. If needle 136 anneals during abrazing process or heating process, then strength of needle 136 isreduced, and needle 136 will likely break during ultrasonic vibration.Because needle 136 cannot anneal, needle 136 cannot be brazed to horn144 in a vacuum braze environment.

In some embodiments, using the brazing process described herein, needle136 may be brazed to horn 144 such that needle 136 will not annealedduring the brazing or heating process.

For example, in one example, needle 136 and horn 144 may be formed ofstainless steel. In this example, needle 136 and horn 144 may be joinedtogether using an acid flux and inert gas (e.g., nitrogen) to facilitatethe brazing material flow during the brazing process. In someembodiments, needle 136 is brazed to horn 144 using an induction brazingmachine which employs heat generated from an electromagnetic fieldcreated by the alternating current from an induction coil. In someembodiments, the braze joint—which may be located in some embodiments atslant portion 147—is protected against oxidation by placing a tube overthe braze joint. After the tube is placed over the brazed joint, gas maybe added. In some embodiments, an additive (e.g., acid flux) may be usedto break surface tension of the metal of needle 136 and the horn 144.

The brazing or heating processes described herein may increase the sizesof the stainless steel type needles which may be used by a deliverydevice to function properly. In certain delivery devices having certaintypes of stainless steel needles attached to a horn, the stainless steelneedle may break based on the needle's strength. For example, where astainless steel needle has a length of about twenty-two times thediameter of the bore diameter, it has been found that themanufacturability decreases and the costs substantially increase.Although, a titanium type needle may be used in certain situations toincrease the length of the needle, a titanium type needle issignificantly more expensive than a stainless steel type needle. Usingthe brazing or heating procedure described herein, delivery device 102may include a stainless steel needle having a length of about onethousand times the diameter of the bore. Such a configuration mayprovide for reduced cost of delivery device 102 by eliminatingcomponents typically used in the construction of a delivery device(e.g., a titanium needle).

In some embodiments, the brazing material may include an alloy, nickel,silver, copper and/or a silver based alloy perform. In some embodiments,the brazing material is supplied as a preformed donut shape, similar tobraze ring 146 illustrated in FIGS. 5 and 6. In some embodiments, thebrazing material to supplied as a wire which may have, for example, a1/32″ diameter.

The brazing material may have a high density. In some embodiments, thebrazing material has a higher density than needle 136 and horn 144. Inthese embodiments, horn 144 may be tuned to different resonantfrequencies based on the volume of braze material applied. For example,in some embodiments, an ultrasonic debridement system includes a 27 KHzdrive signal generator. In this example, the mechanical system may haveto resonate between 25 KHz and 29 KHz to function properly. In somecases, if it is determined that stack assembly 138 is resonating at 31KHz, stack assembly 138 will not function properly. In this example,adding more brazing material can reduce the resonating frequency ofstack assembly 138, and therefore enable stack assembly 138 to functionproperly.

In some embodiments, needle 136 is a fully hardened hypodermic needlewhich is brazed to horn 144. In some embodiments, needle 136 isconnected to horn 144 using a brazing material including silver becausesilver has a melting point below the annealing point of stainless steal.

In some embodiments, needle 136 is not directly connected to horn 144.For example, needle 136 may be connected to a component which isconnected to horn 144. In these embodiments, needle 136 may be describedas being operatively connected to horn 144. However, it should beunderstood that where needle 136 is directly connected to horn 144,needle 136 may be described as being operatively connected to horn 144also.

In one example embodiment, by brazing needle 136 horn 144, the systemdescribed herein may function properly with needle 136 having a lengthof threes inches and a bore size of 0.035 inches.

In some embodiments, crystal stack assembly 142 includes a transducerwhich is configured to generate ultrasonic energy based on a powersignal. For example, as illustrated in FIG. 7, crystal stack assembly142 includes a transducer which is configured to generate ultrasonicenergy based on a power signal which is provided from controller 102.The ultrasonic energy may be applied in a pulsed fashion or continuousfashion.

In some embodiments, the transducer includes piezoelectric crystals. Forexample, as illustrated in FIG. 7, the transducer includes firstpiezoelectric crystal 154, second piezoelectric crystal 156, thirdpiezoelectric crystal 158, and fourth piezoelectric crystal 160. In thisexample, the transducer is operatively connected to first electrode 162,second electrode 164, and third electrode 166.

In some embodiments, the transducer is mounted to mounting member 152such that ultrasonic energy generated by the transducer is transferredto horn assembly 140. The transducer may be configured to generatelongitudinal vibration, transverse vibration, or combinations thereof atdesired frequencies. For example, the number and configuration of thepiezoelectric crystals may be varied to modify the ultrasonic frequencyused for tissue treatment.

As illustrated in FIG. 7, in some embodiments, crystal stack assembly142 may include four piezoelectric crystals. In some embodiments,crystal stack assembly 142 may include at least two piezoelectriccrystals. In some embodiments, as illustrated in FIG. 7, thepiezoelectric crystals may be donut-shaped. In some embodiments, asillustrated in FIGS. 2 and 7, the piezoelectric crystals may beconfigured to receive mounting member and be positioned over mountingmember 152.

In some embodiments, the piezoelectric crystals and electrodes arecompressed between horn assembly 140 and compressor 168. Thepiezoelectric crystals may be assembled such that the polarizations arealigned. In some embodiments, portions of the electrodes are sandwichedbetween the piezoelectric crystals. In some embodiments, the electrodessupply the electric charge to cause these crystals to vibrate.

In some embodiments, as best illustrated in FIG. 7, the ends ofelectrodes 162, 164 and 166 have a crimping feature which allows forcrimping wires to create an electromechanical connection. This type ofconnection is typically a solder connection. Such a configuration allowsfor assembly in a dean room without having soldering fumes or acid fluxdean up.

In some embodiments, the electrodes include a positive electrode thathas a portion that jumps between the positive polarities of thecrystals. In some embodiments, the electrodes include negativeelectrodes that create a safety ground loop circuit. In someembodiments, the negative electrodes are placed between the flatsurfaces of the crystals. In these embodiments, the negative electrodesmay contact the metal components of the stack to complete the groundcircuit.

In some embodiments, compressor 168 is configured to provide compressionforce for crystal stack assembly 142. Compressor 168 may be torqued to apredetermined value to achieve a specific crystal compression.

As illustrated in FIGS. 8 and 9, in some embodiments, compressor 168 mayhave first end portion 172 and second end portion 174. In someembodiments, compressor 168 defines opening or bore 170 that runs fromfirst end portion 172 to second end portion 174. Opening 170 may be usedfor directing the aspiration flow to the vacuum line 108.

In some embodiments, compressor 168 may connect to mounting member 152using any suitable connection method. In some embodiments, first endportion 172 of compressor 168 is connected to mounting member 152 via athreaded connection.

Compressor 168 may include fitting configured to connect to vacuum line108. For example, as illustrated in FIGS. 8 and 9, compressor 168includes barb fitting 169 which is configured to connect to vacuum line108. In this embodiment, barb fitting 169 is integrally formed withcompressor 168. In some embodiments, barb fitting is separate from andoperably connects to compressor 168. Barb fitting 169 may provide aninterference fit with vacuum line 108. Barb fitting 169 may provide forreduced cost of delivery device 102 by eliminating components typicallyused in the construction of a delivery device. In some embodiments,compressor 168 may be referred to as a compression nut.

In some embodiments, delivery device 102 includes an irrigation conduitthat enable delivery device 102 to deliver fluid to a ulcerated woundtissue site, such as beneath an ulcer.

As illustrated in FIG. 9, in some embodiments, the irrigation conduitmay be formed by portions of housing 112 and horn assembly 140. Morespecifically, in some embodiments, the irrigation conduit may formedsuch that fluid may be passed from the inlet of extension 130, throughchannel 119 of nose portion 112, and out of sleeve 117 of nose portion116.

In some embodiments, as best illustrated in FIG. 9, needle 136 andsleeve 117 are secured relative to one another with needle 136 disposedin the inner lumen of sleeve 117. Needle 136 and sleeve 117 define a gapbetween them to form a portion of the irrigation conduit.

In some embodiments, an outlet from the irrigation conduit may bedefined between the terminal end of sleeve 117 and needle 136. Thus,fluid passing into the irrigation conduit in a distal direction passesfrom the irrigation conduit with fluid generally encircling, orcircumscribing the insertion portion of needle 136 and being directedtoward the exposed portion of needle 136.

In some embodiments, delivery device 102 includes a vacuum conduit whichenables delivery device 102 to remove detritus from the ulcerated woundtissue site.

Referring to FIG. 9, the vacuum conduit may be formed by the lumenportions of: (a) horn assembly 140; (b) mounting member 152; and (c)compressor 168. As illustrated in FIG. 9, the vacuum conduit may beformed by lumens formed in needle 136, horn 144, mounting member 152 andcompressor 168.

The vacuum conduit may pass through the transducer as shown in FIG. 9.

In some embodiments, as illustrated in FIG. 9, delivery device 102includes gasket or O-ring 216. In these embodiments, gasket 216 isconfigured to fit into groove portion 148 of horn 144. Such aconfiguration creates a seal between housing 112 and horn 144 such thatfluid within the inner compartment formed by nose portion 116 isprevented from entering within body portion 118 and fluid may bedelivered through the irrigation conduit.

The length of horn assembly 140—which may include needle 136, horn 144,and grooved portion 148 of horn 144—may be any suitable length. In someembodiments, the length of horn assembly 140 is between about 1.5 inchesand about 3.0 inches, between about 1.9 inches and about 2.6 inches,between about 2.1 inches and about 2.5 inches. In some embodiments, thelength of horn assembly 140 is between about 2.2 inches and about 2.35inches, or it is about 2.294 inches.

As illustrated in FIG. 9, delivery device 102 may include gasket 216disposed between body portion 118 and nose portion 116. In someembodiments, during assembly of delivery device 112, body portion 118may slide over stack assembly 138 up to and engage gasket 216.

In some embodiments, as illustrated in FIG. 9, delivery device 102 mayinclude gasket or O-ring 218 for creating a seal between mounting member152 and compressor 168 which may prevent thread lock fluid from runninginto any piezoelectric crystals. In these embodiments, mounting member152 may include groove portion 153 as best illustrated in FIG. 6. Inthis example, gasket 216 is configured to fit into groove portion 153.

In some embodiments, as illustrated in FIG. 9, delivery device 102 mayinclude electrode isolator 220 configure to provide a barrier betweencompressor 168 and housing 112 and isolate certain electrodes (e.g., apositive electrode) from compressor 168.

Electrode isolator 220 may be configured to isolate compressor 168 fromhousing 112 during vibration to minimize the effect of the vibration onhousing 112 by maintaining electrical and mechanical separation.Electrode isolator 220 may be formed from rubber. Electrode isolator 220may be configured to be placed in groove 171 of compressor 168.

In some embodiments, tape made with Kapton® polyimide film may be usedto electrically isolate the positive electrodes from the groundelectrodes and other ground components.

In some embodiments, at each threaded junction, a thread locker isapplied to prevent the threads from loosening and to prevent fluidingress.

In some embodiments, delivery device 102 is a free floating resonator.That is, in this example, delivery device 102 is not fixed such as beingfixed to the housing at the tail end. Such a configuration allows for acost effective manufacture of the delivery device, because, for example,the housing may be formed of a molded plastic material.

In some embodiments, the seal components and vibration isolators areformed of a dampening or insulating material, such as a relatively softpolymeric material, for reducing or inhibiting proximal transmission ofultrasonic energy or other undesirable ultrasonic energy transmission.For example, seal 216 and electrode isolator 220 may be formed ofsilicone, although a variety of materials are contemplated.

Generally, various components of delivery device 102 contemplated fortissue contact are formed of biocompatible and/or other suitablematerials depending upon implementation.

As illustrated in FIG. 1, delivery device 102 may be ergonomicallydesigned, adapted to be hand held (e.g., as a stylet) or otherwiseadapted to be manually operated using a single hand. In someembodiments, delivery device 102 may be adapted to be manipulatedautomatically or semi-automatically (e.g., as part of a robotic system).

In some embodiments, delivery device 102 is pre-tuned to a selectedultrasonic energy frequency or frequency range. For example, anultrasonic energy frequency range from about 25 kHz to about 29 kHzeffectively debrides pathologic tissue located subcutaneously at oraround ulcerated wound tissue while reducing the likelihood of trauma tohealthy soft tissue.

In operation, the tip portions of needle 136 and sleeve 117 may bepercutaneously inserted without having to form an incision in the skin.That is, needle 136 and sleeve 117 may help facilitate atraumatic skinand soft tissue penetration without a need for a separate incision underultrasonic imaging.

Some methods of delivering ultrasonic energy to target a tissue siteinclude connecting delivery device 102 to a vacuum source, an irrigationsource, and a power source of a controller (directly or via a commandmodule). Ultrasonic energy is generated by sending a power signal fromthe command module to the transducer. The ultrasonic energy istransmitted from the transducer to horn assembly 140 such that theexposed portion of needle 136 delivers ultrasonic energy at a frequencythat is pre-selected to debride subcutaneous diseased tissue located ator around an ulcerated wound upon percutaneous insertion of needle 136and sleeve 117 to target tissue site 300.

In some embodiments, a target tissue comprises pathologic tissue, whichmay be identified using high frequency ultrasonic imaging. In someembodiments, a user is able to identify a target tissue site entirely atthe time of a procedure without cutting the skin of the patient.

As previously described, in some embodiments delivery device 102 ispre-tuned to deliver ultrasonic energy at a frequency that reduces thelikelihood of trauma to healthy soft tissue while promoting debridementof the pathologic tissue. The percutaneous, minimally invasive nature ofsuch a procedure facilitates access and treatment of such body tissue aspart of a procedure under local anesthesia.

FIGS. 10A-D comprise intraoperative photos illustrating a technique ofpercutaneous ultrasonic debridement via adjacent percutaneous portalsaccording to the present disclosure. FIG. 10A illustrates a wound priorto performing a procedure outlined in the present description. In someembodiments, external hyperkeratosis is debrided prior to performing anultrasonic debridement procedure. Following administration of localanesthesia, the wound is prepped and draped in typical fashion usingsterile technique. FIGS. 10B-D illustrate a processes of using a 15blade to create access portals via small stab incisions in a cardinalorientation. Larger wound sizes may necessitate additional portals atintercardinal points as well. FIG. 10C also illustrates the hand piecebeing used to debride targeted abnormal tissue below the external tissueof a foot ulcer. FIG. 10D illustrates the wound shown in FIGS. 10A-10Cimmediately following the debridement procedure. In this image, fourcardinal access portals can be seen around the ulcer. According to someembodiments, a sterile dressing is applied immediately after or shortlyafter the debridement procedure is completed.

After performing a percutaneous debridement procedure according to thepresent disclosure, the wound will require time to heal. The amount oftime may depend on the severity and/or size of the wound prior totreatment. In some cases, the healing time will be between about 0 andabout 10 weeks, between about 0.5 and about 5 weeks, or between about 1and about 3 weeks. In some cases, the healing time will be between about1 and 2 weeks.

Exemplary Use of Subcutaneous Debridement in Foot Ulcers

A pilot assessment of percutaneous ultrasonic debridement ofsubcutaneous diseased tissue on chronic refractory neuropathic pedalulcerations was conducted utilizing the equipment and techniquesdisclosed herein. Twelve patients were treated with percutaneousultrasonic debridement using a device according to the presentdisclosure. The average time of wound prior to treatment was 109.2weeks. Of the twelve patients, ten (or about 83%) healed in under twoweeks (average time to healing 1.44 weeks) and without recurrence(average follow up time 24.75 weeks). Average cost estimation of priortreatments was $33,306.50 per patient compared to one in-officepercutaneous procedure at a cost of about $1,200 or in an ambulatorysurgery center at a cost of about $2,500. This study exhibited thefavorable healing time, significant lack of recurrence in ulcerations,and cost savings achievable with the devices and methods of the presentdisclosure.

Patients and Methods

The records of twelve consecutive patients were reviewed. Each patienthad neuropathic ulcerations treated with percutaneous ultrasonictreatment. These recalcitrant wounds were noted to have failedconservative therapy for a minimum of five months. The percutaneousintervention was discussed on multiple previous office visits andperformed either in an ambulatory surgical center treatment room or inthe office of the senior author (LHF).

The Device

The instrument—a device according to the present disclosure—deliversultrasonic energy and simultaneously fragments and aspirates the treatedsubcutaneous tissue. Constant irrigation provides a safety measure toavoid thermal injury to normal tissue.

Technique

Local anesthetic was administered to anesthetize the area of concern.The foot was prepped and draped. The visual ultrasound probe was preppedif performing under visual guidance. If so, vital structures wereidentified. The percutaneous ultrasonic needle (16 gauge) was advancedinto the pathologic region via multiple access points. One technique isto position access portals in the intact skin adjacent to the wounds atcardinal points, adding intercardinal points for larger wounds. SeeFIGS. 10A-10D

Using the needle tip, ultrasonic energy is imparted at a specificfrequency (between about 25 kHz and 29 kHz) designed to debride andaspirate the targeted abnormal tissue, both soft and hard tissue (i.e.,bone) at the same time. The tool and needle also provide irrigation andaspiration to effectively remove diseased and infected tissue. Thesingle use needle and instrument was maneuvered along the region of theulcerated wound with or without a boney prominence until resolved. Ifultrasonic imaging is indicated, it was used concomitantly in thenon-dominant hand to visualize positioning of the instrument.

Following the procedure, a sterile dressing was applied to the wound andportal sites. Daily dressings and non-weight-bearing status were theninitiated.

Of the twelve patients treated with percutaneous ultrasonic debridementduring the study period, none were excluded. The twelve patientsprovided thirteen ulcers on twelve affected feet, with one patienthaving two ulcerations in close proximity (lateral midfoot) that wereboth treated. The average time of wound prior to treatment was 109.2weeks. Of the twelve patients, ten (83%) healed in under two weeks(average time to healing 1.44 weeks) and without recurrence (averagefollow up time 24.75 weeks). FIGS. 12-17 illustrate the before and afterimages of the various ulcerated wounds.

With percutaneous ultrasonic treatment of the subcutaneous tissue at oraround the ulcerated wound, functional ambulation without recurrence isa realistic goal. This technique has proven effective across a widerange of anatomic locations in the foot: the heel, the Charcot midfoot,the plantar 1st metatarsalphalangeal joint, the planter centralmetatarsalphalangeal joint, the hallux, and the interdigital pedallocation. Ten of the twelve (83%) consecutive cases healed withoutrecurrence.

In wounds that occur more proximally or in areas near vitalneurovascular structures, use of visual ultrasound guidance may helpavoid those structures and potential adverse sequelae.

Although the present disclosure has been described with reference tovarious examples, persons skilled in the art will recognize that changesmay be made in form and detail without departing from the spirit andscope of the present disclosure. For example, various modifications andadditions can be made to the exemplary embodiments discussed withoutdeparting from the scope of present disclosure. While the embodimentsdescribed above refer to particular features, the scope of the presentdisclosure also includes embodiments having different combinations offeatures and embodiments that do not include all of the above describedfeatures.

The invention claimed is:
 1. A method of delivering ultrasonic energy toa target tissue using an ultrasonic energy delivery device, the devicecomprising a transducer; an aspiration conduit; an irrigation conduit; ahorn; and a needle, the method comprising: creating at least twopercutaneous access portals surrounding the target tissue; inserting adistal portion of the needle to a first position subcutaneous to thetarget tissue using a first access portal of the percutaneous accessportals and generating ultrasonic energy at the first subcutaneousposition; then inserting the distal portion of the needle to a secondposition subcutaneous to the target tissue through a second accessportal of the percutaneous access portals and generating ultrasonicenergy at the second subcutaneous position.
 2. The method of claim 1,wherein said target tissue is located subcutaneous to an ulceratedwound.
 3. The method of claim 1, further comprising debriding the targettissue with the ultrasonic energy.
 4. The method of claim 3, furthercomprising removing from the first subcutaneous position and/or thesecond subcutaneous position at least some detritus that may have beenproduced by the debriding.
 5. The method of claim 1, wherein the targettissue comprises at least one of the following: soft tissue and hardtissue.
 6. The method of claim 1, further comprising delivering fluid atthe first subcutaneous position and/or the second subcutaneous position.7. The method of claim 1, wherein the ultrasonic energy is deliveredthrough the needle.
 8. The method of claim 1, wherein the target tissuecomprises a foot ulcer.
 9. The method of claim 8, wherein the targettissue located at the first subcutaneous position and/or the secondsubcutaneous position comprises ulcerated wound tissue.
 10. The methodof claim 8, wherein the ulcerated wound tissue comprises bone tissue.11. The method of claim 9, wherein the ulcerated wound tissue comprisesabnormal growth.
 12. The method of claim 11, wherein the abnormal growthcomprises at least one of a bony prominence, calcific tissue, andnecrotic tissue.
 13. The method of claim 1, wherein the needle is afully hardened hypodermic needle.
 14. The method of claim 13, whereinthe needle comprises a stainless steel material.
 15. The method of claim1, wherein the needle includes an exposed portion having a length ofabout 0.75 inches to about 1.5 inches.
 16. The method of claim 1,wherein the needle has a gauge of about 12 to about 25.